Extruded plastic inner spring suspension system and cushion, pad and mattress

ABSTRACT

An linear, extruded, inner spring suspension system, mattresses made therewith, and a process of making the inner spring. The linear spring has a thin resilient vertical wall extending longitudinally in the horizontal direction, which may be pleated with at least one (and preferably a plurality) of pleats which extend longitudinally along the wall. The invention may further have a second wall identical to and parallel to the first wall, which may be connected by plates at top and bottom and at medial points to make a linear spring of rectangular cross section. Embodiments of short length create an inexpensive spring having a generally rectangular platform; longer embodiments create an inexpensive spring in the general shape of a box beam. The linear spring may be produced by an extrusion process, in which polymer compounds are forced through a die in the shape of the linear spring cross section.

STATEMENT REGARDING FEDERALLY FUNDED RESEARCH

This invention was not made under contract with an agency of the US Government, nor by any agency of the US Government.

FIELD OF THE INVENTION

This invention relates generally to cushions and pads and specifically to springs for use in cushions, mattresses and pads.

CROSS-REFERENCE TO RELATED APPLICATIONS

N/A

BACKGROUND OF THE INVENTION

Inner spring pads, inner spring cushions, and inner spring mattresses have a complex structure and construction. In the simplest terms, the typical inner spring cushion or mattress has fabric and possibly foam layers at top and bottom, a larger framework defining the overall shape, a smaller framework within the larger framework designed to hold springs, and numerous springs attached to the smaller framework. In common practice, the larger design may be wooden slats while the smaller framework is heavy gauge wire.

This structure exacts a heavy burden at the time manufacture, both in terms of logistics and labor. The disparate components (fabrics, foams, wooden slats, wire, springs, and so on) must be brought together for the construction. Construction of the known inner spring mattress must be carried out step-by-step, frequently by hand. Because of the bulk of the mattress, it is often considered economically impractical to ship them long distances, as is often done with other consumer goods. Thus, cushions may end up being constructed by hand or by only partially automated processes at locations having relatively high labor costs. The same causes and effects may apply to construction of other inner spring pads.

The springs of typical pads or cushions tend to be made of heavy gauge wire, formed into either the traditional spring shapes or newer wire spring shapes the maker believes offer better characteristics. Other springs may be constructed by molding, a process which while cheaper than drawing and shaping heavy gauge wire, is still not optimal in terms of cost or labor intensity.

A search of the collection of granted US Patents and published US applications finds some items in those class and subclass combinations related to cushion, pad or mattress construction.

US Patent Publication No. 20040117913, depicts a conventional type of mattress having coil springs and a resilient top surface member with a firm or rigid bottom member.

U.S. Pat. No. 6,782,575 depicts another device of conventional design: a foam mattress having resilient members.

U.S. Pat. No. 6,317,912 depicts a hybrid design having both air cells and coil springs. The sidewalls or edges are constructed of a foam rubber.

U.S. Pat. No. 6,286,167 depicts a mattress having generally rectangular sleeves each having within it generally cylindrical or tubular support elements or “logs”. The sleeves are stated to be constructed of “sheer” material (see column 2, lines 31-32), and seem to have no support function.

U.S. Pat. No. 6,243,900 is related to the '913 publication and has the same inventor and similar structures: a rigid bottom plate and a core of coil springs, rendering it less relevant,.

U.S. Pat. No. 5,172,436 teaches a rigid (see column 1, line 58) core portion 3 which is in turn is covered by rigid protecting plate 4. Vertical corrugations and generally vertical cross members run across the mattress from side to side.

U.S. Pat. No. 5,137,592 is related to water bed mattresses and shows a rib or baffle for use inside the mattress. These ribs do not serve a support function, however, and at column 2 lines 66 et seq are identified as “also” being the material of the mattress itself, which in turn is identified (col. 2, lines 49 through 59) as being flexible. A resilient water bed mattress would of course defeat the function of a water bed mattress.

U.S. Pat. No. 5,027,458 relates to collapsible mattresses, and depicts a foam latticework which apparently will support an imposed load in one dimension and yet allow itself to be collapsed in some other dimension.

U.S. Pat. No. 4,713,854 depicts a mattress having numerous foam arches within the core.

U.S. Pat. No. 4,143,435 depicts another foam core mattress, this one having a corrugated foam core and no springs.

U.S. Pat. No. 3,766,580 depicts generally cylindrical plastic springs which have corrugations along the walls of the cylinder to provide spring action. These corrugated springs are cylindrical and not box beam or I-beam arrangements.

U.S. Pat. No. 3,262,137 depicts “bellows” springs in which the exit of air from the spring provides an effect much like a hydraulic cylinder. These bellows springs are cylindrical and not I-beam arrangements. Linear extrusion of such springs would be either impossible or extremely, difficult.

There does not appear to be in this collection of prior art any suggestion that a spring might be manufactured by straightforward linear extrusion methods.

There does not appear to be in this collection of prior art any suggestion that a mattress may be manufactured using lengthy linear springs.

It would be advantageous to provide an extremely inexpensive extrude-able spring.

It would further advantageous to provide an extremely inexpensive and labor-competitive method of constructing a mattress or other pad.

It would further be advantageous to provide a linear vertical spring.

It would further be advantageous to provide a linear box beam spring.

It would further be advantageous to provide a spring product by means of an extremely low cost extrusion process.

SUMMARY OF THE INVENTION

General Summary

The present invention teaches an inner spring suspension system, cushions made therewith, and a process of making the inner spring. The inner spring of the invention may be a linear spring having a resilient vertical wall extending longitudinally in the horizontal direction. The thin resilient wall of the invention may be pleated with at least one (and preferably a plurality) of pleats which extend longitudinally along the wall. The spring may be oriented with the longitudinal linear axis (the long axis) vertical, horizontal, or at any angle at all.

In embodiments, the invention may further have a second wall identical to and parallel to the first wall. The two walls may be connected by plates at top and bottom and at medial points to make a linear spring of rectangular cross section. Shorter length sub-embodiments of such embodiments create an inexpensive spring having a generally rectangular platform, while longer sub-embodiments create an inexpensive spring in the form of a box beam.

The pads and cushions of the invention may be produced for use in furniture, automobiles, beds, exercise mats, work pads and any other use for which cushions and pads are customarily used. Dies used to create the invention (and thus the linear springs of the invention) may be of any size from tiny (sub-millimeter dimensions) to quite large (multiple meter dimensions), may have quite weak spring constants (very soft springs) to quite strong spring constants (very hard springs), the thickness of the springs may be varied, may be high impact or low impact material or consistency, may be any color or size and so on.

In embodiments, a linear spring is produced by an extrusion process, in which polymer compounds are forced through a die in the shape of the linear spring cross section.

Summary in Reference to Claims

It is therefore a first aspect, advantage, objective and embodiment of the present invention to provide a linear spring comprising:

-   -   1) a first resilient wall having a top edge, a bottom edge, a         vertical height, a horizontal length in a first horizontal         dimension, and a thickness in a second horizontal dimension         perpendicular to the first horizontal dimension;     -   2) the wall having at least one horizontal lengthwise pleat.

It is therefore another aspect, advantage, objective and embodiment of the present invention to provide a linear spring wherein the pleat extends a portion of the horizontal length.

It is therefore another aspect, advantage, objective and embodiment of the present invention to provide a linear spring wherein the pleat extends the entire horizontal length.

It is therefore another aspect, advantage, objective and embodiment of the present invention to provide a linear spring further comprising:

-   -   3) a first connector disposed at one edge.

It is therefore another aspect, advantage, objective and embodiment of the present invention to provide a linear spring wherein the first connector extends linearly along the top edge.

It is therefore another aspect, advantage, objective and embodiment of the present invention to provide a linear spring wherein the first connector comprises at least one vertical extension defining a channel, the extension and channel extending linearly along the top edge.

It is therefore another aspect, advantage, objective and embodiment of the present invention to provide a linear spring further comprising:

-   -   4) a second resilient wall having a second wall top edge, a         second wall bottom edge, a second wall vertical height equal to         the vertical height of the first wall, a second wall horizontal         length in the first horizontal dimension equal to the horizontal         length of the first wall, and a thickness in the second         horizontal dimension, the second wall having at least one         horizontal lengthwise pleat;     -   5) a top plate extending from the top edge of the first         resilient wall to the second resilient wall top edge; and     -   6) a bottom plate extending from the bottom edge of the first         resilient wall to the second resilient wall bottom edge.

It is therefore another aspect, advantage, objective and embodiment of the present invention to provide a linear spring further comprising:

-   -   7) at least one hole in at least one plate.

It is therefore another aspect, advantage, objective and embodiment of the present invention to provide a linear spring further comprising:

-   -   8) a second resilient wall having a second wall top edge, a         second wall bottom edge, a second wall vertical height equal to         the vertical height of the first wall, a second wall horizontal         length in the first horizontal dimension equal to the horizontal         length of the first wall, and a thickness in the second         horizontal dimension, the second wall having at least one         horizontal lengthwise pleat;     -   9) at least one plate extending from a pleat of the first         resilient wall to a pleat of the second resilient wall.

It is therefore another aspect, advantage, objective and embodiment of the present invention to provide a mattress or cushion comprising:

-   -   1) a top plate having a periphery, a bottom plate having a         periphery, the bottom plate located at a first distance from the         top plate, each plate having a distal outer surface and a         proximate inner surface,     -   2) a resilient side wall connecting the peripheries of the top         and bottom plates, and     -   3) at least one linear spring between inner surfaces of the top         and bottom plates, the linear spring extending from the top         plate to the bottom plate and having at least a first resilient         wall having a top edge at the top plate inner surface, a bottom         edge at the bottom plate inner surface, a vertical height equal         to the first distance, a horizontal length in a first horizontal         dimension, and a thickness in a second horizontal dimension         perpendicular to the first horizontal dimension;     -   4) the first resilient wall of the linear spring having at least         one horizontal lengthwise pleat.

It is therefore another aspect, advantage, objective and embodiment of the present invention to provide a mattress further comprising:

-   -   5) at least one metal reinforcement located at the junction of         one plate and the resilient side wall.

It is therefore another aspect, advantage, objective and embodiment of the present invention to provide a mattress wherein the linear spring further comprises:

-   -   3a) at least a second resilient wall having a top edge at the         top plate inner surface, a bottom edge at the bottom plate inner         surface, a vertical height equal to the vertical height of the         first resilient wall, a horizontal length in the first         horizontal dimension equal to the length of the first resilient         wall, a thickness in a second horizontal dimension perpendicular         to the first horizontal dimension;     -   3b) the second resilient wall of the linear spring having at         least one horizontal lengthwise pleat;     -   3c) a top plate extending from the top edge of the first         resilient wall to the second resilient wall top edge; and     -   3d) a bottom plate extending from the bottom edge of the first         resilient wall to the second resilient wall bottom edge.

It is therefore another aspect, advantage, objective and embodiment of the present invention to provide a mattress further comprising:

-   -   6) at least a second linear spring between inner surfaces of the         top and bottom plates, the second linear spring extending from         the top plate to the bottom plate and having at least first and         second resilient walls each having a top edge at the top plate         inner surface, a bottom edge at the bottom plate inner surface,         a vertical height equal to the first distance, a horizontal         length in a first horizontal dimension, and a thickness in a         second horizontal dimension perpendicular to the first         horizontal dimension, the first and second resilient walls         connected at top edges by a top plate and connected at bottom         edges by a bottom plate;     -   7) the first and second resilient walls of the second linear         spring each having at least one horizontal lengthwise pleat.

It is therefore another aspect, advantage, objective and embodiment of the present invention to provide a mattress wherein the first linear spring further comprises:

-   -   3e) a horizontal plate extending from the at least one         lengthwise pleat of the first resilient wall to the at least one         lengthwise pleat of the second resilient wall.

It is therefore yet another aspect, advantage, objective and embodiment of the present invention to provide a linear spring made by a process of:

-   -   1) providing a die having an extrusion aperture, the extrusion         aperture being an opening having a height in a first dimension         substantially longer than the aperture width in a second         perpendicular dimension,     -   2) extruding through the die a polymer which becomes resilient         after extrusion to form an elongate body having the cross         section of the die;     -   3) separating a first length of the elongate body into at least         one linear spring.

It is therefore yet another aspect, advantage, objective and embodiment of the present invention to provide a linear spring made by a process further comprising:

-   -   2a) cooling the elongate body after extrusion.

It is therefore yet another aspect, advantage, objective and embodiment of the present invention to provide a linear spring made by a process wherein the step 2a) of cooling the elongate body after extrusion further comprises:

-   -   2b) water cooling the elongate body after extrusion.

It is therefore yet another aspect, advantage, objective and embodiment of the present invention to provide a linear spring made by a process further comprising:

-   -   2c) applying tension to the elongate body as it is extruded.

It is therefore yet another aspect, advantage, objective and embodiment of the present invention to provide a linear spring made by a process wherein the extrusion aperture further comprises a generally straight aperture having at least one angle therein, whereby the elongate body extruded therethrough has at least one longitudinal pleat therein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional view of a first embodiment of the invention, having “W” section springs.

FIG. 2 is a cross sectional view of a second embodiment of the invention.

FIG. 3 is an end view of a third embodiment of the invention, such as might be extruded by the apparatus and process of the first embodiment of the invention, or might be built up using the device of the second embodiment of the invention.

FIG. 4 is an end view of a fourth embodiment of the invention, such as might be extruded by the apparatus and process of the first embodiment of the invention, or might be built up using the device of the second embodiment of the invention.

FIG. 5 is a partially cross sectional view of a fifth embodiment of the invention.

FIG. 6 is a top perspective view of a sixth embodiment of the invention, a cushion finished with sidewalls and top surfaces which hide the nature of the cushion.

FIG. 6A is a top perspective view of an alternative sixth embodiment of the invention, a mattress finished with sidewalls and bottom and top surfaces.

FIG. 7 is a perspective view of a seventh embodiment of the invention.

FIG. 8 is a perspective view of an eighth embodiment; a mattress, pad or cushion made according to the invention.

FIG. 8A is a perspective view of an alternative eighth embodiment, a mattress, pad or cushion according to the invention.

FIG. 9 is a face view of a ninth die embodiment of the present invention.

FIG. 10 is a partial perspective view of a tenth embodiment of the present invention.

FIG. 11 is a partial perspective view of an eleventh embodiment of the present invention.

FIG. 12 is a partial perspective view of a twelfth embodiment of the present invention.

FIG. 13 is a low-angle perspective partial view of a thirteenth embodiment of the present invention.

FIG. 14 is a cross sectional view of a plastic extrusion apparatus and process according to a first embodiment of the invention.

INDEX OF REFERENCE NUMERALS

-   Hopper 100 -   Polymer in hopper 102 -   Polymer extruded into shape 102″ -   Linear Inner Spring 102′″ -   Die 104 -   Rollers (Tensioner) 106 -   Water 108 -   Travelling Cutter/Separator 110 -   Screw 112 -   Area/Heater 114 -   Water Tank 116 -   Pump 118 -   Table 120 -   Connector 152 -   Straight section 154 -   W-Pleat 156 -   Channel 158 -   Extension 150 -   Connector 202 -   Straight section 204 -   Pleat 206 -   Channel 208 -   Extension 210 -   I-Beam Spring Embodiment 300 -   Pleated Linear Springs of 1^(st) Cross-section 302 -   Pleated Linear Springs of 2^(nd) Cross-section 304 -   Pleated Linear Springs of 3^(st) Cross-section 306 -   Pleated Linear Springs 402, 404, 422, 424 -   Bottom Plates 406, 426 -   Top Plates 408, 428 -   Horizontal (Medial) Pleated Plates 410, 430 -   Bottom Plate Pleats 432 -   Low Density Pleats 434 -   Higher Density Pleats 436 -   Pleated Linear Spring 502 -   Bottom Plate 506 -   Top Plate 508 -   Horizontal Plate 510 -   Bottom Hole 532 -   Top Hole 536 -   Gap 540 -   Inter-Beam Gap 542 -   Linear Spring Unit 550 -   Cushion 600 -   Top Surface Layer 602 -   Sidewall Layer 604 -   Mattress 606 -   Surface Layer 608 -   Sidewall Layer 610 -   Connector 702 -   Linear Support 704 -   Pleated Linear Spring 706 -   Edge 802 -   Sidewall 806 -   I-Beam of Pleated Linear Springs 808 -   Gap 810 -   I-Beam 808A -   Gap 801A -   Die 902 -   Fastener 904 -   Extrusion Aperture 906 -   Straight Section 908 -   Pleated Section 910 -   Pleated Linear Springs 1002, 1004 -   Bottom Plates 1006 -   Top Plates 1008 -   First Pleated Section 1010 -   Second Pleated Section 1012 -   I-beam of Pleated Linear Springs 1014 -   First Pleat 1101 -   Second Pleat 1103 -   Extruded Wire Seat 1105 -   I-beam of Pleated Linear Springs 1208 -   First Pleated Section 1210 -   Second Pleated Section 1212 -   I-beam Flange 1214 -   First I-beam 1308 -   Second I-beam 1310 -   Edge Flange 1312 -   Cushion/Mattress Edge Spring 1314

DETAILED DESCRIPTION

FIG. 1 is a cross sectional view of a first embodiment of the invention, having “W” section springs. The presently favored pleats of the invention are not all the same size, on the contrary some pleats are deeper than others, resulting in a “W” cross section pleat 156. Straight section 152 may connect the pleated section to connector 152, having channel 158 and extension 150. The spring, outside the plane of FIG. 1, is simply a longitudinally extruded device of indefinite length. Being polymer, it may be manufactured at enormous cost advantage over conventional springs.

FIG. 2 is a cross sectional view of a second embodiment of the invention. A wall such as wall 502 of FIG. 5 may have at least one horizontal lengthwise pleat is advantageous as the pleats serve generally the same purpose as the individual coils of a known metal inner spring: each pleat may serve to bend slightly under imposed loads, adding to the resiliency and altering the spring constant of the final spring when compared to the resiliency and spring constant of a simple flat vertical wall. Thus the form of FIG. 2 is achieved. The pleat may extend a portion of the horizontal length (if the cross section is altered during manufacture or cross-sectionally diverse linear springs are joined end to end after initial manufacture) or the pleat may extend the entire horizontal length of the linear spring.

A connector may be disposed at one or both of the top and bottom edges of the spring: the connector, like the pleats, may be integral to the linear spring and may be produced by the extrusion process using a die having the appropriate shape of aperture. The connector may extend linearly along the edges, and may comprise at least one, preferably two vertical extensions or arms defining a channel therebetween.

Linear extruded spring 200, one presently preferred embodiment and best mode now contemplated has connector 202. Channel 208 may be defined by extension 210 or by means of additional extensions: the channel may be the space between arms of an extension, or may be contained within a single extension. Other forms of connectors include series of hooks, a single longitudinal linear hook and so on. In the presently preferred embodiment, the extension 210 is formed of the same material as the resilient, pleated vertical wall of the spring, and is formed as part of an extrusion process from a die having the extrusion present in the shape of the die, thus allowing for a single step manufacturing process. In alternative embodiments, the extension may be formed from the same die but of a different material (for example, a die fed from two different reservoirs) or may be formed separately and later attached to the spring wall's top and/or bottom edges. In yet other alternative embodiments, connector 202 may be a series of fasteners (such as studs, snaps, brads, nails, screws and the like) or may be formed by adhesion (i.e. glue, bonding agents, or even heat bonds).

Straight section 204 and pleat 206 may extend longitudinally/lengthwise along the linear spring for a portion of the length of the spring or for the entire length of the spring. In FIG. 2, this would be represented by extension out of the plane of the diagram and thus is not shown.

FIG. 3 is an end view of a third embodiment of the invention, such as might be extruded by the apparatus and process of the first embodiment of the invention, or might be built up using the device of the second embodiment of the invention. I-Beam Spring Embodiment 300 may have different cross sections at different locations. As already noted, a section may be pleated or may be straight (see FIG. 1 or FIG. 2) or the pleats may be “W” section (FIG. 1) or any other shape (FIG. 2). However, the present Figure shows that the pleats may vary in thickness. Pleated linear springs of 1^(st) Cross-section 302 may be of lesser thickness than pleated linear springs of 2^(nd) cross-section 304. Pleated linear springs of 3^(rd) cross-section 306 may be of another thickness. The result is that different spring constants may be achieved within the span of a single wall of the invention. For example, section 302 may be designed for an imposed load of 70 kg., while section 304 may be designed for an imposed load of 150 kg. and section 306 may be designed for an imposed load of 250 kg. The result is that individuals of different weights may use the pad of the invention without discomfort.

It may be seen that the “beam” embodiment of FIG. 3 may conceivably be constructed by building up smaller embodiments of the invention but in the preferred mode may be made by a simpler process. In particular, the entire beam (two resilient vertical walls with plates connecting them) may be extruded as a single linear unit using a die and process of somewhat increased complexity. Thus the process embodiment of FIG. 14 may be used to produce the linear spring beam embodiment of FIG. 3 or the single linear vertical wall embodiment of FIG. 2. The use of a simpler die and extrusion process to produce the single linear wall embodiment reduces manufacturing costs at the stage of production of the spring, but if a beam construction is desired for the finished cushion, pad or mattress, then an additional step of construction of the beam embodiment becomes necessary. Use of a more complex die and process to extrude the beam embodiment imposes some extra cost at the step of spring construction but allows an easier construction process of a mattress having beams therein. Of course, a mattress/cushion embodiment may use the single vertical wall linear spring as the basic spring element without any beam embodiment at all.

FIG. 4 is an unshaded end view of a fourth embodiment of the invention, such as might be extruded by the apparatus and process of the first embodiment of the invention, or might be built up using the device of the second embodiment of the invention. In this embodiment, the complexity of the assembly renders a built up construction preferable at the present time. (Note that this view is not shaded, the pleats are closely set.)

Pleated linear springs 402, 404, 422, 424 are connected by bottom plates 406, 426, top plates 408, 428, and horizontal plates 410, 430 in a medial position with low density pleats.

Bottom Plate Pleats 432 may extend along some but not all of the bottom plate, by means of careful control of the extrusion process or by extrusion of the bottom plate in pieces and later assembly.

Low density pleats 434 and higher density pleats 436 demonstrate that the device may have pleats of different sizes, different numbers, and other different properties, in the same unit. Numerous smaller pleats 436 mixed with low density pleats 434 may be used to provide a desired spring constant to the mattress.

It may be seen that a number of beam unit embodiments as shown in FIG. 3 may be combined as shown in FIG. 4 to create a wider spring or an entire mattress.

FIG. 5 is an unshaded partially cross sectional view of a fifth embodiment of the invention. Pleated linear spring 502, bottom plate 506, top plate 508, and horizontal plate 510 are considerably shortened from previous embodiments. It will be recalled that FIG. 14 depicts a separator such as a cutter, which during manufacture separates the extruding polymer into individual linear springs of a desired length. The longitudinal length of the springs may vary widely within the scope of the invention. While previous embodiments depicted linear springs of up to several feet in length, the individual linear spring unit 550 of the present embodiment may be only a few inches or smaller in the lengthwise dimension. Linear spring unit 550 may be seen to be approximately square in platform. Gap 540 may allow air flow, and may provide working space for different units to sway slightly under differential loads.

Use of relatively short linear spring units imposes a small production burden, as more individual units must be handled. The advantage of such short springs is that individual linear extruded spring units may be used as replacements, potentially even one for one replacements, of traditional coil springs. Thus, a cushion or mattress of traditional design (frame, wire frame numerous individual springs) might be constructed using the device of the invention. Note that such a construction would negate many of the advantages of building a mattress embodiment using the linear springs of the invention, and the preferred mattress embodiment uses longer springs and avoids traditional mattress construction techniques.

Bottom hole 532 and top hole 536 may allow air flow, save weight, or save material in construction. The individual pleats are not shaded, however the pleats are numerous and closely set.

FIG. 6 is a top perspective view of a sixth embodiment of the invention, a cushion finished with sidewalls and top surfaces which hide the nature of the cushion. Cushion 600 may be a pillow or bolster, or may be a seat cushion or the like. Finished, with the interior construction covered by top plate layer 602 and sidewall layer 604 (as well as a bottom layer not shown) the cushion or pillow appears identical to any other cushion. The top, bottom and side layers may include not only cloth but also foam or other types of mattress/cushion construction.

FIG. 6A is a top perspective view of a variant of the sixth embodiment of the invention, a mattress finished with sidewalls and surfaces which hide the structures of the invention. Mattress 606 is finished with a surface layer 610 and a sidewall layer 608 of cloth or foam, in the same manner as the exterior of any other mattress.

A sidewall embodiment may be used as shown in FIG. 7, which is a perspective view of a seventh embodiment of the invention. Connector 702 having linear support 704 on pleated linear spring 706 may be used to outline the platform of a mattress or other pad and serve as a sidewall to the final mattress.

FIG. 8 is a perspective view of an eighth embodiment; a mattress, pad or cushion made according to the invention. Top and bottom plates are removed to show one potential construction. Edge 802 is one sidewall 806, a resilient vertical wall according to the invention. I-beam of pleated linear springs 808 is similar to the embodiment of FIG. 3. A number of such beam embodiments may extend from side to side across the width of the mattress, separated from each other by gaps such as gap 810.

In sub-embodiments of the embodiment, the beams may entirely fill the space without gaps therebetween. In yet other sub-embodiments, the beams may run from head to foot of the mattress embodiment, or they may extend for less than the full length or width of the mattress. FIG. 8A is a perspective view of an alternative eighth sub-embodiment, a mattress, pad or cushion according to the invention in which gap 810A is comparable in size to beam 808A, leaving a substantial gap between beams.

FIG. 10 is a partial perspective view of a tenth embodiment of the present invention. Pleated Linear Springs 1002, 1004, may rise in parallel from bottom plate 1006 to top plate 1008, and may be secured thereto or extruded therewith to form I-beam of pleated linear springs 1014.

First pleated section 1010 and second pleated section 1012 on the top plate 1008 may have different pleat structures. Different numbers of pleats may be used, different gaps between pleats, different sizes and pleats may be used in different sections of top plate 1008, or in different sections of the pleated linear springs or bottom plates, which may all be pleated in embodiments.

Variation in pleating arrangements may enhance structural integrity, durability, comfort or simply be used to control spring constant and other aspects of the invention.

FIG. 11 is a partial perspective view of an eleventh embodiment of the present invention. First pleat 1101 and second pleat 1103 may have different cross-sections in structure, configuration, size, shape, thickness and other variables. Such variations have the same benefits as those discussed in the preceding paragraph: they may enhance structural integrity, durability, comfort or simply be used to control spring constant and other aspects of the invention.

Extruded wire seat 1105 may be a passage or partial passage through a portion of the edge of the mattress construction. This extruded seat 1105 may be of the same material as that of the rest of the construction. The wire seat 1105 may be dimensioned and configured to accept therein a wire reinforcement as discussed in regard to reference numeral 604, and may be a connector such as connector 208 (FIG. 2) or may cooperate therewith to hold the wire reinforcement seated securely to the mattress. Note that in advanced extrusion techniques, the wire may actually be placed in the wire seat 1105 at the moment of extrusion of the mattress edge/mattress spring, thus greatly simplifying construction. It will be appreciated that this construction and reinforcement technique is not limited to mattress edges: the spring depicted in FIG. 11 may be an internal spring having one, two or more wire reinforcements as well as being a mattress edge.

FIG. 12 is a partial perspective view of a twelfth embodiment of the present invention. I-beam of pleated linear springs 1208 has first pleated section 1210 and second pleated section 1212, which have pleats having different configurations, shapes, sizes, etc, and also have pleated sections having different characteristics as well. The I-beam may also have I-beam flange 1214 used in assembly of the final pad or cushion of the device to aid joining of the individual I-beams.

This embodiment of FIG. 12 may in alternative embodiments have horizontal plates in medial positions between the top and bottom. (FIG. 4 shows plates near the middle of the mattress.) Such horizontal plates, like the top and bottom plates, may have holes in them, may have pleats and may have variable thicknesses and so on.

FIG. 13 is a low-angle perspective partial view of a thirteenth embodiment of the present invention. First I-beam 1308 and second I-beam 1310 may be extruded separately and then joined.

One additional detail of construction depicted in FIG. 13 (and FIG. 11) is edge flange 1312 extruded with a mattress edge spring 1314. This edge flange 1312 allows easier construction, by presenting a surface similar to I-beam flange 1214 (FIG. 12).

In alternative embodiments, a mattress of the invention may have layers of foam above the top plate, providing extra padding and altering the spring characteristics of the mattress under imposed loads. The spring may be oriented with the longitudinal linear axis (the long axis) vertical, horizontal, or at any angle desired. Dies used to create the invention (and thus the linear springs of the invention) may be of any size from tiny (sub-millimeter dimensions) to quite large (multiple meter dimensions), may have quite weak spring constants (very soft) to quite strong spring constants (very hard), may be any color or size and so on.

FIG. 14 is a cross sectional view of a plastic extrusion apparatus and process according to a first embodiment of the invention.

Hopper 100 may contain an amount of a polymer in a particle state such as a small pellets or the like. This particulate polymer is melted into a ductile state inside of heated area 114. A suitable polymer for the task may be polypropylene or related compounds. In general, it is desired to produce a resilient wall as the final product, and the choice of polymer, inclusions and production method details will depend on the desire for that resiliency, for ease of production and for reduced cost of production as well.

Screw 112 turns and forces the polymer pellets 102 through the area 114. During the heating, the individual pellets of polymer lose their identity as they melt into a single liquid mass of polymer that is forced down the area 114 and into die 104. Heat bands may optionally be used on the area.

Polymer in the manufacturing process passes through die 104 and is thus shaped into a desired shape. The shape assumed by the polymer in the die may be the shape of the die channel itself, or it may be another shape which is a function of the shape of the die, the thermo-mechanical properties of the particular polymer, the pressure exerted, the tension exerted, and other factors. In the case of a simple die, the cross sectional shape produced is usually identical to the cross section of the opening of the die 104. (For example, the die of FIG. 9 produces a beam spring of the present invention). In alternative embodiments, more than one die may be used, for example, to provide more exact dimensions and more precise tolerances.

Water tub 116 holds water 108, which is recirculated by pump 118, which may also control precisely the temperature of the water 108, thus strictly controlling the properties of the cooling polymer 102″. Tensioner 106 (a set of rollers) may exert tension on the polymer as it is extruded. The tension applied by tensioner 106 may also alter the final shape of the product produced by the process.

Cutter/separator 110 may at measured longitudinal intervals separate individual work pieces or finished products by separating lengths of the extruded polymer 102″ into individual polymer linear inner springs such as linear inner spring 102′″. Note that cutter 110 may advantageously be a “travelling” cutter which actually moves along with the product 102″ so as to provide more efficient cutting. Linear springs produced by this method may advantageously be the entire length or width of the seat cushion or mattress in which they will be used. For example, a linear spring for use with one standard size of mattress might be 72 inches (approximately 183 centimeters) in length. A linear spring for use in a seat cushion, however, might be only 16 inches (approximately 41 centimeters) in length. In the alternative, the linear spring of the invention may be shorter than the length of the pad in which it will be used, as discussed in reference to FIG. 5.

The result of production of an inner spring by this process of FIG. 1 is a “linear” inner spring having a resilient wall having a top edge and a bottom edge. The inner spring resilient wall may also have a vertical height and a horizontal or longitudinal length in a first horizontal dimension: the direction of the extrusion. It may also have a thickness in a second horizontal dimension perpendicular to the first horizontal dimension; this thickness may be represented as the width of the die through which the polymer passes.

FIG. 9 is a face view of an alternative die embodiment of the present invention. Die 902 may be a rectangular body as shown, or may be other shapes. The extrusion face of die 902 is shown, the face at which the polymer enters the die is not shown, but may be a substantially different shape from the face shown. Several dies may be also be used in order to provide precision shaping of the final product.

Extrusion aperture 906 is the cross sectional view of the passage through the die 902 through which the polymer passes during the production operation. Note that the extrusion aperture 906 may not necessarily have the same cross section as other portions of the passage through the die. For example, the polymer may be fed into the die through more than one passage (with the passages then joining with the die body), or through a passage of a different shape at the reservoir side and so on.

The cross sectional view of aperture 906 may be a shape for a simple beam embodiment of the invention. Straight section 908 may produce a section of flat bottom for the pad or mattress, while pleated section 910 may produce a section of the wall of the beam having pleats. Straight and pleated sections may be mixed, as shown by the top section of the beam. As the polymer is extruded out of the plane of FIG. 9, the shape produced may extend longitudinally with the same cross section, unless the manufacturing choice is made to alter manufacturing conditions during the run so as to alter the cross section in mid-manufacture.

A wall having at least one horizontal lengthwise pleat is advantageous as the pleats serve generally the same purpose as the individual coils of a known metal inner spring: each pleat may serve to bend slightly under imposed loads, adding to the resiliency and altering the spring constant of the final spring when compared to the resiliency and spring constant of a simple flat vertical wall. The pleat may extend a portion of the horizontal length (if the cross section is altered during manufacture or cross-sectionally diverse linear springs are joined end to end after initial manufacture) or the pleat may extend the entire horizontal length of the linear spring. As the polymer is extruded out of the plane of FIG. 9, the shape produced may extend longitudinally with the same cross section, unless the manufacturing choice is made to alter manufacturing conditions during the run so as to alter the cross section in mid-manufacture.

The disclosure is provided to allow practice of the invention by those skilled in the art without undue experimentation, including the best mode presently contemplated and the presently preferred embodiment. Nothing in this disclosure is to be taken to limit the scope of the invention, which is susceptible to numerous alterations, equivalents and substitutions without departing from the scope and spirit of the invention. The scope of the invention is to be understood from the appended claims. 

1. A spring comprising: 1) a first resilient wall having a top edge, a bottom edge, a vertical height, a horizontal length in a first horizontal dimension, and a thickness in a second horizontal dimension perpendicular to the first horizontal dimension; 2) the wall having at least one horizontal lengthwise pleat.
 2. The spring of claim 1, wherein the pleat extends a portion of the horizontal length.
 3. The spring of claim 1, wherein the pleat extends the entire horizontal length.
 4. The spring of claim 1, further comprising: 3) a first connector disposed at one edge.
 5. The spring of claim 4, wherein the first connector extends linearly along the top edge.
 6. The spring of claim 5, wherein the first connector comprises at least one vertical extension defining a channel, the extension and channel extending linearly along the top edge.
 7. The spring of claim 1 further comprising: 4) a second resilient wall having a second wall top edge, a second wall bottom edge, a second wall vertical height equal to the vertical height of the first wall, a second wall horizontal length in the first horizontal dimension equal to the horizontal length of the first wall, and a thickness in the second horizontal dimension, the second wall having at least one horizontal lengthwise pleat; 5) a top plate extending from the top edge of the first resilient wall to the second resilient wall top edge; and 6) a bottom plate extending from the bottom edge of the first resilient wall to the second resilient wall bottom edge.
 8. The spring of claim 7, further comprising: 7) at least one hole in at least one plate.
 9. The spring of claim 1 further comprising: 8) a second resilient wall having a second wall top edge, a second wall bottom edge, a second wall vertical height equal to the vertical height of the first wall, a second wall horizontal length in the first horizontal dimension equal to the horizontal length of the first wall, and a thickness in the second horizontal dimension, the second wall having at least one horizontal lengthwise pleat; 9) at least one plate extending from a pleat of the first resilient wall to a pleat of the second resilient wall.
 10. A mattress comprising: 1) a top plate having a periphery, a bottom plate having a periphery, the bottom plate located at a first distance from the top plate, each plate having a distal outer surface and a proximate inner surface, 2) a resilient side wall connecting the peripheries of the top and bottom plates, and 3) at least one linear spring between inner surfaces of the top and bottom plates, the linear spring extending from the top plate to the bottom plate and having at least a first resilient wall having a top edge at the top plate inner surface, a bottom edge at the bottom plate inner surface, a vertical height equal to the first distance, a horizontal length in a first horizontal dimension, and a thickness in a second horizontal dimension perpendicular to the first horizontal dimension; 4) the first resilient wall of the linear spring having at least one horizontal lengthwise pleat.
 11. The mattress of claim 10, further comprising: 5) at least one metal reinforcement located at the junction of one plate and the resilient side wall.
 12. The mattress of claim 10, wherein the linear spring further comprises: 3a) at least a second resilient wall having a top edge at the top plate inner surface, a bottom edge at the bottom plate inner surface, a vertical height equal to the vertical height of the first resilient wall, a horizontal length in the first horizontal dimension equal to the length of the first resilient wall, a thickness in a second horizontal dimension perpendicular to the first horizontal dimension; 3b) the second resilient wall of the linear spring having at least one horizontal lengthwise pleat; 3c) a top plate extending from the top edge of the first resilient wall to the second resilient wall top edge; and 3d) a bottom plate extending from the bottom edge of the first resilient wall to the second resilient wall bottom edge.
 13. The mattress of claim 12, further comprising: 6) at least a second linear spring between inner surfaces of the top and bottom plates, the second linear spring extending from the top plate to the bottom plate and having at least first and second resilient walls each having a top edge at the top plate inner surface, a bottom edge at the bottom plate inner surface, a vertical height equal to the first distance, a horizontal length in a first horizontal dimension, and a thickness in a second horizontal dimension perpendicular to the first horizontal dimension, the first and second resilient walls connected at top edges by a top plate and connected at bottom edges by a bottom plate; 7) the first and second resilient walls of the second linear spring each having at least one horizontal lengthwise pleat.
 14. The mattress of claim 12, wherein the first linear spring further comprises: 3e) a horizontal plate extending from the at least one lengthwise pleat of the first resilient wall to the at least one lengthwise pleat of the second resilient wall.
 15. A linear spring made by the process of: 1) providing a die having an extrusion aperture, the extrusion aperture being an opening having a height in a first dimension substantially longer than the aperture width in a second perpendicular dimension, 2) extruding through the die a polymer which becomes resilient after extrusion to form an elongate body having the cross section of the die; 3) separating a first length of the elongate body into at least one linear spring.
 16. The linear spring made by the process of claim 15, further comprising: 2a) cooling the elongate body after extrusion.
 17. The linear spring made by the process of claim 16, wherein the step 2a) of cooling the elongate body after extrusion further comprises: 2b) water cooling the elongate body after extrusion.
 18. The linear spring made by the process of claim 15, further comprising: 2c) applying tension to the elongate body as it is extruded.
 19. The linear spring made by the process of claim 15, wherein the extrusion aperture further comprises a generally straight aperture having at least one angle therein, whereby the elongate body extruded therethrough has at least one longitudinal pleat therein. 